<!DOCTYPE html>  
<html>  
<head>  
  <meta charset="utf-8">  
  <meta http-equiv="X-UA-Compatible" content="IE=edge">  
  <style type="text/css">  
    .mainwrap{
      margin: 0 auto;  
      height: 300px;  
    }  
    .left{  
      width: 150px;  
      height: 100%;  
      background: yellow;  
      float: left;  
    }  
    .right{  
      width: 150px;  
      height: 100%;  
      background: pink;  
      float: right;  
      position: relative;  
      top: -100%;  
    }  
    .center{  
      width: 100%;  
      height: 100%;  
      background: green;  
      /*float: left;*/  
    }  
  	.a-center {
     	text-align: center;
     }
     .v-center {
     	vertical-align: middle;
     }
  </style>  
</head>  
<body>  
  <div class="mainwrap">  
      <div class="left"></div>  
      <div class="center a-center">
      	QWERTYUIOLPASDFGHJKASDFGHJZXCVBNM
      </div>  
  </div>  
  <br>
  <div>
  	Nothing	
  </div>
  
  
</body>  
</html>